A court has dropped charges against Augusto Pinochet's widow and two of his children who had been indicted as accomplices of Chile's late dictator over alleged tax evasion and the use of false passports.

Lucia Hiriart and two of Pinochet's daughters, Lucia and Veronica, together with his long-time secretary, Monica Ananias, were cleared by the Santiago court of appeals. The decision not to prosecute follows a three-year investigation into the use of the now-defunct Riggs Bank in Washington and several offshore investment trusts by Pinochet, who died last month aged 91, his children and aides.

The court ruled that charges of using false passports by Pinochet's son, Marco Antonio, and several officials would be dropped, but it upheld indictments against Marco Antonio and a lawyer, Oscar Aitken, for alleged tax evasion. Charges of tax evasion were dropped against another of Pinochet's daughters, Jacqueline.

"If we continue like this the properties [in his estate] are going to be returned to the Pinochet family. They are going to divide 5,000m pesos (£838m) among the heirs," said a prosecutor, Alfonso Insunza, who criticised Chile's government for not pursuing the case more energetically. Investigations into the family fortune have been stymied by a web of international bank accounts and fake identity papers.